(1) Field of the invention
The present invention relates generally to a lock for manually-operated pump dispensers such as trigger sprayers, and more particularly to a lock that prevents movement of the trigger and reciprocation of the sprayer pump element when the lock is engaged.
(2) Description of Related Art
There are numerous prior art patents directed to child-resistant locking features used in fluid dispensers of the general type to which this invention relates. Generally a fluid dispenser of the type involved in the present invention is a relatively low-cost, hand-held trigger sprayer which may be manually operated by pulling a trigger to pump liquid from a container attached to the sprayer through a nozzle orifice at the front of the sprayer. Fluid dispensers of this type have a variety of features which have become well-known in the industry. For example, the dispenser may have a dedicated spray nozzle which produces a fixed spray pattern such as a narrow stream or a fine mist. Alternately, the fluid dispenser may be of the type which has a variable spray pattern. Still other fluid dispensers permit a foaming liquid to be dispensed as either a foam or a liquid spray. The child-resistant lock of the present invention is equally well-suited for use in each of these types of fluid dispensers, as well as, virtually any other type of fluid dispenser.
Regardless of the type of fluid dispenser used, the fluids dispensed could be chemicals which are harmful or fatal if swallowed. Further, the chemicals could be caustic and thus are harmful to individuals if they come in contact with the skin for any appreciable length of time. These harmful effects are frequently more pronounced in children because of their relatively small size and sensitive tissues. In addition, because children may not be able to read or understand textual or graphical warnings printed on the containers, they may not be able to appreciate the danger associated with the chemicals and thus have an increased risk of coming in contact with and being injured by these chemicals.
Although children may be more susceptible to being injured by chemicals dispensed from trigger sprayers, they are easier to protect from the harmful effects of the chemicals by physically locking the containers. Children may be prevented from accessing chemicals contained in a trigger sprayer by incorporating a lock on the trigger sprayer. Simply by requiring disengagement of a lock mechanism on a trigger sprayer before the trigger can be operated, a significant number of children may be prevented from dispensing fluid from the sprayer and others may be inhibited from dispensing fluid from the sprayer for a sufficient length of time so that an adult may be alerted to the potentially harmful acts of the child and take appropriate action.
In the past, various types of locking mechanisms have been developed for sprayers to impede children from coming into contact with potentially harmful chemicals dispensed by locking the trigger and pump elements of the sprayer against movement. One example is disclosed in U.S. Pat. No. 5,114,049. This reference discloses a latch which is pivotally connected to a trigger. The trigger is connected to the housing for pivoting movement in actuating a pump to dispense a liquid from the dispenser. When in the "on" position, the latch prevents the trigger from pivoting. However, the latch is flexible and may be deflected from the "on" position so that the latch does not interfere with pivoting the trigger. Thus, when the latch is deflected to the "off" position, the trigger may be actuated and the fluid may be dispensed from the fluid dispenser. Therefore, the user must use one motion to deflect the latch upward or downward and a second motion to actuate the trigger backward and forward in order to dispense liquid. However, these two motions may be accomplished with one hand. By grasping the fluid dispenser in one hand, the latch may be disengaged with the index finger while the trigger is actuated with the remaining three fingers of the hand. Therefore, with a simple grasping motion, the latch may be unintentionally disengaged and the fluid may be dispensed. Also, in order to repeatedly pivot the trigger it is necessary to continue to hold the latch in its "off" position.
It would be desirable in a trigger sprayer having a lock that prevents the reciprocating movement of the pump element and the pivoting movement of the trigger, to position the lock on the sprayer so that it could not be inadvertently disengaged by simply grasping the sprayer and positioning the fingers of the hand over the trigger, and to construct the lock mechanism so that it would remain in its disengaged condition without the need to hold the lock in its disengaged condition while manipulating the trigger of the sprayer.